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Scandinavian Journal of Medicine &... Dec 2023Muscle strain injuries in the human calf muscles are frequent sports injuries with high recurrence. Potential structural and functional changes in the medial head of the...
BACKGROUND
Muscle strain injuries in the human calf muscles are frequent sports injuries with high recurrence. Potential structural and functional changes in the medial head of the musculus gastrocnemius (GM) and the associated aponeurosis are not well documented.
PURPOSE
To test whether a GM muscle strain injury affects muscle fascicle length, pennation angle, and the morphology of the deep aponeurosis at rest and during muscle contraction long time after the injury. Additionally, electromyography (EMG) of the GM and the soleus muscle during a unilateral heel rise was measured in the injured and uninjured calf.
METHODS
GM fascicle length, pennation angle, and aponeurosis thickness was analyzed on dynamic ultrasonography (US) recordings in 10 participants with a chronic calf strain. In addition, US images taken across the distal portion and mid-belly of the GM were analyzed at three different ankle positions. EMG recordings were obtained during a unilateral heel rise.
RESULTS
The pennation angle of the injured distal GM was significantly larger compared to the uninjured GM in the contracted, but not the relaxed state. Pennation angle increased more in the injured compared to the uninjured GM during contraction. Fascicle length was shorter in the most distal portion of the injured GM. Fascicles at the distal portion of the injured GM showed a pronounced curvilinear shape as the muscle contracted and the aponeurosis was enlarged in the injured compared to the uninjured GM. The ratio between GM and soleus EMG activity showed a significantly higher relative soleus activity in the injured compared to the healthy calf.
CONCLUSION
The greater change in pennation angle and curvilinear fascicle shape during contraction suggest that a long-term consequence after a muscle strain injury is that some muscle fibers at the distal GM are not actively engaged. The significantly enlarged aponeurosis indicates a substantial and long-lasting connective tissue involvement following strain injuries.
Topics: Humans; Aponeurosis; Muscle, Skeletal; Electromyography; Muscle Fibers, Skeletal; Muscle Contraction; Ultrasonography; Sprains and Strains
PubMed: 37621063
DOI: 10.1111/sms.14472 -
The Journal of Craniofacial Surgery Oct 2023The aim of this study was to observe and analyze the anatomical and histological characteristics of the upper tarsus in Asian.
OBJECTIVE
The aim of this study was to observe and analyze the anatomical and histological characteristics of the upper tarsus in Asian.
METHODS
A total of 15 Asians (14 adults, 1 child) were used. The sagittal sections with thickness of 3 μm in the middle of the upper eyelid were prepared and stained with hematoxylin-eosin, Masson trichrome and anti-smooth muscle actin antibody staining, and then were observed and photographed under light microscopy.
RESULTS
On the sagittal section, the upper end of the tarsus was connected with the Müller muscle and the part of the posterior layer of the levator aponeurosis; the lower end was the inflated part of the palpebral margin; the superficial surface was connected with the pretarsal fascia; and the deep surface was connected with Müller muscle aponeurosis and palpebral conjunctiva. Histologically, the tarsus was similar to the structure between dense fibrous connective tissue and cartilage, and its main structures include meibomian glands and its ducts, accessory lacrimal glands, glands of Moll, glands of Zeis, eyelash hair follicles, Riolan muscle, blood vessels, and collagen fibers. Through the observation of the tarsus of a child, compared with the adult specimen, the meibomian gland tissue was more abundant; the collagen fibers density was significantly lower and arranged orderly; the blood vessel density was significantly higher; α-SMA positive smooth muscle cells could be seen in the upper end of the tarsus and its superficial and deep surfaces.
CONCLUSIONS
In this study, the internal and adjacent anatomical structures of the upper tarsus in Asians were observed under a microscope, and according to the histological characteristics, the tarsus was divided into 3 parts and 3 types. Through the preliminary analysis, the tarsus was likely to show different histological characteristics in different individuals and age groups of Asians. There was a certain correlation between the degree of meibomian gland atrophy, the degree of collagen fibrosis and the density of blood vessel in the tarsus.
Topics: Adult; Child; Humans; Oculomotor Muscles; Ankle; Asian People; Eyelids; Collagen
PubMed: 37259202
DOI: 10.1097/SCS.0000000000009397 -
Actas Dermo-sifiliograficas Dec 2017
Topics: Aged; Aponeurosis; Biopsy; Calcinosis; Female; Fibroblasts; Fibroma; Forearm; Humans; Neoplasms, Connective Tissue; Subcutaneous Tissue; Ultrasonography
PubMed: 28108007
DOI: 10.1016/j.ad.2016.05.023 -
Annals of Plastic Surgery Aug 2020Suprazygomatic aponeurotic McLaughlin (SAM) myoplasty technique for facial reanimation is based on the classical McLauglin's lengthening temporalis myoplasty with a... (Review)
Review
BACKGROUND
Suprazygomatic aponeurotic McLaughlin (SAM) myoplasty technique for facial reanimation is based on the classical McLauglin's lengthening temporalis myoplasty with a series of new modifications. A comprehensive review of previously described other orthodromic temporalis myoplasty techniques is also included to give a succinct comparison.
METHODS
Twelve adult patients of facial palsy underwent SAM myoplasty for a period of 4 years. Three had congenital facial palsy, 4 patients had facial palsy secondary to acoustic neuromas, 3 were posttraumatic, and 2 patients had Bell's palsy.
RESULTS
Range of modiolus excursion achieved as measured at 3 months postoperatively on reanimation in our patients was 5 mm to 20 mm with an average of 12.6 mm. With SAM myoplasty technique, we were able to achieve excellent result in 4 patients and good results in 8 patients as evaluated with May and Druker scoring system.
CONCLUSIONS
Suprazygomatic aponeurotic McLaughlin myoplasty for facial reanimation demonstrates a successful modification of the classical McLaughlin lengthening temporalis myoplasty, making it more customizable, simple, and predictable by taking the level of transection to the temporalis aponeurosis without the need for zygomatic osteotomy. A new classification of orthodromic temporalis myoplasty based on level of transections is also proposed for the first time. Good to excellent outcomes coupled with high patient satisfaction and low morbidity should make this technique popular among the facial reanimation surgeons.
Topics: Adult; Aponeurosis; Bell Palsy; Facial Paralysis; Humans; Plastic Surgery Procedures; Temporal Muscle
PubMed: 32049759
DOI: 10.1097/SAP.0000000000002266 -
Journal of Biomechanics May 2021Quadriceps intramuscular anatomy is typically described in two dimensions. However, anatomical descriptions indicate fascicles in the quadriceps may have a...
Quadriceps intramuscular anatomy is typically described in two dimensions. However, anatomical descriptions indicate fascicles in the quadriceps may have a three-dimensional orientation. The purpose of this investigation was to quantify the maximum force generating capacity of the individual quadriceps' muscles in three dimensions. Muscle architectural parameters were obtained from three cadaver specimens (two female) and input into a geometry-based multiple fascicle muscle force model. Vastus lateralis, vastus medialis, and rectus femoris had partitions which could be defined based on differences in the sense and direction of fascicles between partitions. Vastus lateralis and rectus femoris were bipennate due to partitions sharing an aponeurosis. Vastus lateralis deep and superficial partitions exerted posterior- (maximum: -29 ± 5 N) and anterior-directed (maximum: 58 ± 15 N) forces on their shared distal aponeurosis. Rectus femoris medial and lateral partitions exerted medial- (maximum: -38 ± 17 N) and lateral-directed (maximum: 19 ± 12 N) forces on their shared proximal aponeurosis. All vastus medialis fascicles ran along the proximal-distal axis. However, fascicles arising near the lesser trochanter also ran along the superficial-deep axis, while fascicles arising from the linea aspera ran along the medial-lateral axis. Thus, vastus medialis could be divided into longus and oblique partitions. Due to the large pennation angle, vastus medialis oblique could exert maximum medial-directed (-219 ± 93 N) and proximal-directed (279 ± 168 N) forces at approximately -40° and -70° knee flexion, respectively, indicating dual roles for vastus medialis oblique dependent on knee flexion angle.
Topics: Cadaver; Female; Femur; Humans; Quadriceps Muscle
PubMed: 33711598
DOI: 10.1016/j.jbiomech.2021.110347 -
Journal of the Mechanical Behavior of... Oct 2020Aponeuroses are stiff sheath-like components of the muscle-tendon unit that play a vital role in force transmission and thus locomotion. There is clear importance of the...
Aponeuroses are stiff sheath-like components of the muscle-tendon unit that play a vital role in force transmission and thus locomotion. There is clear importance of the aponeurosis in musculoskeletal function, but there have been relatively few studies of aponeurosis material properties to date. The goals of this work were to: 1) perform tensile stress-relaxation tests, 2) perform planar biaxial tests, 3) employ computational modeling to the data from 1 to 2, and 4) perform scanning electron microscopy to determine collagen fibril organization for aponeurosis tissue. Viscoelastic modeling and statistical analysis of stress-relaxation data showed that while relaxation rate differed statistically between strain levels (p = 0.044), functionally the relaxation behavior was nearly the same. Biaxial testing and associated modeling highlighted the nonlinear (toe region of ~2-3% strain) and anisotropic (longitudinal direction linear modulus ~50 MPa, transverse ~2.5 MPa) tensile mechanical behavior of aponeurosis tissue. Comparisons of various constitutive formulations showed that a transversely isotropic Ogden approach balanced strong fitting (goodness of fit 0.984) with a limited number of parameters (five), while damage modeling parameters were also provided. Scanning electron microscopy showed a composite structure of highly aligned, partially wavy collagen fibrils with more random collagen cables for aponeurosis microstructure. Future work to expand microstructural analysis and use these data to inform computational modeling would benefit this work and the field.
Topics: Anisotropy; Aponeurosis; Collagen; Stress, Mechanical; Tendons
PubMed: 32957196
DOI: 10.1016/j.jmbbm.2020.103889 -
Folia Medica Cracoviensia 2019Spigelian hernia (SH) is a rare ventral interstitial hernia occurring through a defect in the transversus abdominis aponeurosis (Spigelian fascia). Spigelian fascia is... (Review)
Review
Spigelian hernia (SH) is a rare ventral interstitial hernia occurring through a defect in the transversus abdominis aponeurosis (Spigelian fascia). Spigelian fascia is found between the lateral border of the rectus abdominis muscle and the semilunar line, which extends from the costal cartilage to the pubic tubercle. In other words, Spigelian line is where the transversus abdominis muscle ends in an aponeurosis characterized by a congenital or acquired defect in the Spigelian aponeurosis. Pediatric cases of SH are either congenital or acquired due to trauma, previous surgery or increased intra-abdominal pressure. SH in combination with ipsilateral cryptorchidism may constitute a new syndrome, as such cases are extremely rare in the literature is new syndrome is characterized by the following congenital, ipsilateral disturbances: SH, absence of inguinal canal and gubernaculum and the homolateral testis found within the Spigelian hernia sac (a hernia sac containing undescended testis). The aim of this study is to emphasize some typical findings of this specific entity, and, hence, the necessity for a thorough investigation of the origin of the SH.
Topics: Child; Cryptorchidism; Fascia; Female; Hernia, Ventral; Humans; Male; Syndrome
PubMed: 31904751
DOI: 10.24425/fmc.2019.131381 -
European Journal of Applied Physiology Aug 2022Measurement of medial gastrocnemius (MG) tendon length using ultrasonography (US) requires the muscle-tendon junction (MTJ) to be located. Previously, the MG MTJ has...
PURPOSE
Measurement of medial gastrocnemius (MG) tendon length using ultrasonography (US) requires the muscle-tendon junction (MTJ) to be located. Previously, the MG MTJ has been tracked from different proximo-distal locations near the MTJ, which could influence estimates of tendon length change due to the different characteristics of the aponeurosis and tendon. We used US to evaluate the effect of tracking point location on MG MTJ displacement during maximal and submaximal (10, 20 and 30% of the non-injured maximal) isometric plantar flexion contractions.
METHODS
Displacement behaviour of MTJ was tracked from (1) the exact MTJ; and (2) from an insertion point of a muscle fascicle on the aponeurosis 1.3 ± 0.6 cm proximal to the MTJ, in both limbs of patients with unilateral Achilles tendon rupture (ATR) (n = 22, 4 females, 42 ± 9 years, 177 ± 9 cm, 79 ± 10 kg).
RESULTS
In the non-injured limb, displacement (1.3 ± 0.5 cm vs. 1.1 ± 0.6 cm) and strain (6.7 ± 2.8% vs. 5.8 ± 3.3%) during maximal voluntary contraction were larger when tracking a point on the aponeurosis than when tracking the MTJ (both p < 0.001). The same was true for all contraction levels, and both limbs.
CONCLUSION
Tracking a point on the aponeurosis consistently exaggerates estimates of tendon displacement, and the magnitude of this effect is contraction intensity-dependent. When quantifying displacement and strain of the Achilles tendon, the MTJ should be tracked directly, rather than tracking a surrogate point proximal to the MTJ. The latter method includes part of the aponeurosis, which due to its relative compliance, artificially increases estimates of MTJ displacement and strain.
Topics: Achilles Tendon; Aponeurosis; Female; Humans; Isometric Contraction; Muscle, Skeletal; Ultrasonography
PubMed: 35522277
DOI: 10.1007/s00421-022-04958-8